Wisdom collections from civilisations with little or no contact share themes, structures and sometimes near-identical phrasing. The resemblance has several causes, and borrowing is only one of them.
They address the same recurring situations
Every settled society produces disputes over property, unequal friendships, the temptation to speak carelessly and the problem of a superior who is wrong.
Advice literature grows around exactly these pressure points because they recur in every generation and are not solved by any particular political arrangement.
Convergent content follows from convergent circumstance, which is why the parallels are strongest in the practical material and weakest in the theological framing. Two collections may agree closely about creditors and disagree entirely about what the world is.
Oral transmission imposes a shared form
Material that must be remembered without writing tends toward short units, balanced clauses, contrast and repetition. These features aid recall directly.
The result is that unrelated traditions arrive at a similar shape: paired lines in which the second half completes or reverses the first, so that a speaker who has the opening can recover the rest.
The form is doing mnemonic work, so its recurrence tells us about the conditions of transmission rather than about contact between the cultures involved.
Trade routes did carry material
Contact was more extensive than is often assumed, and administrative and commercial exchange moved texts along with goods across considerable distances.
Scribal training in several regions involved copying foreign material, which provides a plausible route for specific sayings to travel and be adapted.
Establishing an actual line of borrowing for any individual saying is difficult, and scholars usually treat such claims cautiously rather than as settled.
Collections contradict themselves consistently
Wisdom books across traditions place opposing maxims near each other, advising both caution and boldness, both silence and speech.
This is a feature of the genre rather than editorial carelessness. The collections supply a repertoire of responses, leaving the reader to judge which situation they are in.
A reader looking for a system will find these books incoherent. A reader looking for material to think with will find them arranged sensibly.
Where the traditions genuinely diverge
The differences appear in what is said to underwrite the advice: an impersonal order, a divine command, an ancestral obligation, a natural pattern.
That layer is where each tradition is most distinctive, and it is also the part least likely to survive translation into another setting.
Reading only the practical maxims therefore flattens the traditions considerably, since the shared surface sits on foundations that were never the same.